HLA, PTPN22 and PD-1 associations as markers of autoimmunity in neuromyelitis optica

Background: Neuromyelitis optica (NMO) is a disease with autoimmune characteristics. A genetic autoimmune dependency for NMO has not been clarified in detail. Objective: To investigate immunogenetic aspects of NMO. Methods: Forty-one patients with NMO and 42 patients with multiple sclerosis (MS) were diagnosed in a population-based Caucasian cohort. HLA DQA1, DQB1, and DRB1 alleles were determined. Polymorphisms in programmed death 1 (PD-1) PD-1.3 G/A and protein tyrosine phosphatase non-receptor 22 (PTPN22) 1858 C/T were genotyped. Results: In the NMO group 15% had other autoimmune disorders and 39% had family occurrence of autoimmunity, comparable to MS. A higher frequency of a family history (17%) of NMO and MS was found in the NMO group (p